1. Field of the Invention
The present invention relates to a sewing machine having an embroidery stitching function, and more particularly relates to a sewing machine having a function for damping the vibration of an embroidering frame which may be produced during embroidery stitching operation and further relates to an embroidering frame having a function for damping the vibration of itself, so that the embroidery stitching operation may be performed smoothly and steadily while the embroidering frame is held as being stabilized on the sewing machine bed.
2. Prior Art
Recently the sewing machine having a drive mechanism for driving an embroidering frame has been generally used. The drive mechanism includes a carriage for removably holding the embroidering frame. The carriage is partly extended out of the sewing machine frame and driven into and out of the sewing machine frame so as to be moved in X-Y direction, thereby to move the embroidering frame in X-Y direction accordingly relative to a vertically reciprocating needle on the surface of a machine bed. Thus the embroidery stitching operation is performed.
In case the embroidering frame is moved in X-Y direction on the surface of the machine bed, it is required that the embroidering frame is moved in a stabilized condition wherein the embroidering frame is constantly in close contact with the surface of the machine bed. According to the prior art, as shown in FIG. 7(a), the embroidering frame f mounted to the carriage c will often fail to correctly contact the surface of the machine bed b and float up from the surface of the machine bed b. This is because the precision is not sufficient in the parts of the drive mechanism and/or in the assembly thereof, or in the connecting part between the embroidering frame f and the carriage c.
On the other hand, as shown in FIG. 7(b), since the embroidering frame f is generally rigid and fails to have a movable part at the arm portion thereof by which the embroidering frame f is mounted to the carriage c, the embroidering frame f is often pressed against the surface of the machine bed b with a strong force which will produce a friction between the embroidering frame f and the surface of the machine bed b, thus hindering the movement of the embroidering frame f.
Further, the driving movement of a drive motor and the resultant operation movement of the embroidering frame drive mechanism may be transmitted to the embroidering frame to vibrate the same. This will often hinder the smooth and steady movement of the embroidering frame. Further, the vertically reciprocating needle will vibrate the embroidering frame up and down with the instantaneous force given to the cloth held by the same as the needle is moved up through the cloth. In any events, such vibrations will give adverse influence to formation of stitches and to the stitched result of embroidery patterns.
It is, therefore, a primary object of the invention to provide an embroidery sewing machine having a function for damping the vibrations of embroidering frame which may be caused during embroidery stitching operation.
It is another object of the invention to provide an embroidery sewing machine having a function for absorbing the vibrations of embroidering frame which may be caused during embroidery stitching operation.
It is another object of the invention to provide an embroidery sewing machine having a function for elastically pressing the embroidering frame against the surface of machine bed with an optimal force.
It is another object of the invention to provide a vibration damping or absorbing means which is simple in structure and in smooth in operation.
It is another object of the invention to provide elastic means in connection with the carriage for pivotally holding the embroidering frame to normally press the embroidering frame against the surface of machine bed.
It is another object of the invention to provide a means for regulating the pivotal movement of the embroidering frame to normally maintain an optimal contact between the embroidering frame and the surface of machine bed.
It is another object of the invention to provide elastic means at a proper part of the embroidering frame to normally deflect the embroidering frame to the surface of machine bed.
It is still another object of the invention to provide the carriage with an inclined surface as is progressively lowered towards the machine bed so as to normally deflect the embroidering frame to the surface of machine bed.
The other objects and advantages will be apparent in the following detailed description of the invention.
For attaining the objects, the invention substantially comprises an embroidering frame having a cloth held thereon to be stitched, a drive mechanism for moving the embroidering frame, means including a carriage for holding the embroidering frame and operatively connected to the drive mechanism to be moved thereby to move the embroidering frame in X-Y direction relative to a vertically reciprocating needle on the surface of a machine bed, and means for absorbing the vibrations of the embroidering frame which may be caused during embroidery stitching operation, wherein the vibration absorbing means includes a spring member provided in connection with the carriage or in connection with the embroidering frame so as to yieldably press the embroidering frame against the surface of the machine bed, and wherein the carriage is provided with an inclined surface as it is progressively lowered towards the machine bed to have the embroidering frame mounted thereto such that the embroidering frame may yieldably deflect up and down. The invention further comprises means for regulating the angular movement of the embroidering frame to normally maintain an optimal contact between the embroidering frame and the surface of machine bed.